src/main/java/eu/svjatoslav/sixth/e3d/gui/RenderingContext.java

   1 /*
   2  * Sixth 3D engine. Author: Svjatoslav Agejenko.
   3  * This project is released under Creative Commons Zero (CC0) license.
   4  */
   5 package eu.svjatoslav.sixth.e3d.gui;
   6
   7 import eu.svjatoslav.sixth.e3d.geometry.Point2D;
   8 import eu.svjatoslav.sixth.e3d.gui.humaninput.MouseEvent;
   9 import eu.svjatoslav.sixth.e3d.gui.humaninput.MouseInteractionController;
  10
  11 import java.awt.*;
  12 import java.awt.image.BufferedImage;
  13 import java.awt.image.DataBufferByte;
  14 import java.awt.image.WritableRaster;
  15
  16 /**
  17  * Rendering context that contains all the information that is needed to render the scene.
  18  */
  19
  20 public class RenderingContext {
  21
  22     public static final int bufferedImageType = BufferedImage.TYPE_4BYTE_ABGR;
  23
  24     public final Graphics2D graphics;
  25
  26     /**
  27      * Pixels of the rendering area.
  28      * Each pixel is represented by 4 bytes: alpha, blue, green, red.
  29      */
  30     public final byte[] pixels;
  31
  32     /**
  33      * Width of the rendering area in pixels.
  34      */
  35     public final int width;
  36
  37     /**
  38      * Height of the rendering area in pixels.
  39      */
  40     public final int height;
  41
  42     /**
  43      * Center of the screen in screen space (pixels).
  44      * This is the point where (0,0) coordinate of the world space is rendered.
  45      */
  46     public final Point2D centerCoordinate;
  47
  48     /**
  49      * Zoom factor. The bigger the value, the more zoomed in the view is.
  50      */
  51     public final double zoom;
  52     final BufferedImage bufferedImage;
  53     /**
  54      * Number of frame that is currently being rendered.
  55      * Every frame has its own number.
  56      */
  57     public int frameNumber = 0;
  58
  59     /**
  60      * UI component that mouse is currently hovering over.
  61      */
  62     private MouseInteractionController objectPreviouslyUnderMouseCursor;
  63     /**
  64      * Mouse click event that needs to be processed.
  65      * This event is processed only once per frame.
  66      * If there are multiple objects under mouse cursor, the top-most object will receive the event.
  67      * If there are no objects under mouse cursor, the event will be ignored.
  68      * If there is no event, this field will be null.
  69      * This field is set to null after the event is processed.
  70      */
  71     private MouseEvent mouseEvent;
  72     /**
  73      * UI component that mouse is currently hovering over.
  74      */
  75     private MouseInteractionController currentObjectUnderMouseCursor;
  76
  77     public RenderingContext(final int width, final int height) {
  78         this.width = width;
  79         this.height = height;
  80         this.centerCoordinate = new Point2D(width / 2d, height / 2d);
  81         this.zoom = width / 3d;
  82
  83         bufferedImage = new BufferedImage(width, height, bufferedImageType);
  84
  85         final WritableRaster raster = bufferedImage.getRaster();
  86         final DataBufferByte dbi = (DataBufferByte) raster.getDataBuffer();
  87         pixels = dbi.getData();
  88
  89         graphics = (Graphics2D) bufferedImage.getGraphics();
  90         graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
  91         graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
  92     }
  93
  94     public void prepareForNewFrameRendering() {
  95         mouseEvent = null;
  96         currentObjectUnderMouseCursor = null;
  97     }
  98
  99     public MouseEvent getMouseEvent() {
 100         return mouseEvent;
 101     }
 102
 103     public void setMouseEvent(MouseEvent mouseEvent) {
 104         this.mouseEvent = mouseEvent;
 105     }
 106
 107     /**
 108      * Called when given object was detected under mouse cursor, while processing {@link #mouseEvent}.
 109      * Because objects are rendered back to front. The last method caller will set the top-most object, if
 110      * there are multiple objects under mouse cursor.
 111      */
 112     public void setCurrentObjectUnderMouseCursor(MouseInteractionController currentObjectUnderMouseCursor) {
 113         this.currentObjectUnderMouseCursor = currentObjectUnderMouseCursor;
 114     }
 115
 116     /**
 117      * @return <code>true</code> if view update is needed as a consequence of this mouse event.
 118      */
 119     public boolean handlePossibleComponentMouseEvent() {
 120         if (mouseEvent == null) return false;
 121
 122         boolean viewRepaintNeeded = false;
 123
 124         if (objectPreviouslyUnderMouseCursor != currentObjectUnderMouseCursor) {
 125             // Mouse cursor has just entered or left component.
 126             viewRepaintNeeded = objectPreviouslyUnderMouseCursor != null && objectPreviouslyUnderMouseCursor.mouseExited();
 127             viewRepaintNeeded |= currentObjectUnderMouseCursor != null && currentObjectUnderMouseCursor.mouseEntered();
 128             objectPreviouslyUnderMouseCursor = currentObjectUnderMouseCursor;
 129         }
 130
 131         if (mouseEvent.button != 0 && currentObjectUnderMouseCursor != null) {
 132             // Mouse button was clicked on some component.
 133             viewRepaintNeeded |= currentObjectUnderMouseCursor.mouseClicked(mouseEvent.button);
 134         }
 135
 136         return viewRepaintNeeded;
 137     }
 138
 139 }